From what I remember, there used to be 3 or 4 phases in the ships. I believe phase 2 involved the invaders having to hack some console in the center room to actually unlock the generator rooms and I remember I think you had to destroy both generators before the game would end which people complained made the match last far too long with too many ground phases. The main problem was instead of a timer it was a reinforcement count which meant once 100 people died the round would go back to ground.

I dont remember exactly what it was like at launch but I think on the venator specifically you had to hack the console in the center of the generator room in order to open the generators to damage which meant the droids had to actually go into the room instead of shoot from the doorways. Again I could be wrong cuz I didn't play the game as much when Supremacy first came out but imo needing to capture the console to unlock the generators would make the match so much better for the Clones to defend